The purpose of this case report is to demonstrate direct access to obliterated root canals and root canal treatment with the aid of guided endodontics (GE) created with a three-dimensional (3D) printer using 3D imaging techniques. A female patient presented to our clinic with the complaint of percussion sensitivity in the left upper second premolar. According to the clinical and radiographic examination of the tooth, root canal obliteration was detected, extending 2 mm below the cementoenamel junction of the tooth. The root canals were localized using cone beam computed tomography (CBCT). The endodontic guide was prepared by transferring the images obtained with the intraoral scanner and the CBCT data to a 3D printer with a special computer program. Root canals were accessed with the help of this guide using endodontic bur. Root canal treatment of the patient was completed with routine endodontic procedures. After the treatment with the aid of GE, it was observed that the patient’s symptoms disappeared and the tooth was in function. In the treatment of teeth with obliterated root canals, many complications can be prevented by providing a safe endodontic intervention with the aid of GE obtained with 3D printers.Keywords: Apical periodontitis, guided endodontics, pulp canal calcification.